FOLIO BIOLOGI

MRSM PENGKALAN HULU

TITLE:

ENDANGERED ECOSYSTEM

NAME: MOHAMAD IZZAT HAFIZ B. SULAIMAN

CLASS: 404

COLLAGE NUMBER: 08022

TEACHER: NORITA DARJO

DEFORESTATION….

Deforestation is an act of extensive cutting down or burning the trees in the forest. The vast areas of forests are being cleared away for extracting timber or fuel wood, agriculture and urban development.There are many impacts of deforestation such as Soil erosion, flash floods and landslides. Landslidesoccurs when the top layer of soil loosens and slides down because of rains for a long period of time during rainy seasons.

The landslides happen because of the stability of soil is lost due to deforestation. Clearing of trees causes the loss of tree leaves to protect the soil from the impact of raindropsand also causes the loss of tree roots to hold the soil in places.Thus, the soil is exposed directly to the force of the rain. Heavy rainfall will easily washed .away the top layer of the soil. This leads to soil erosion. The eroded soil is carried away by water and may be deposited into the river. During heavy rains, rainwater flows quickly into rivers because there is no retention of water by plant roots as well as water catchment areas.

Due to silting in the rivers, the water flows is blocked. Thus, water flows inland and causes flash flood in low areas. Soil erosion also leads to DEPLETION OF MINERALS for the land. The land cannot be used for cultivation. Extinction of flora and fauna Deforestation leads to the loss of habitats for many species of flora and fauna. This will cause an increased rate of extinction of plants and animals. As a results, it reduces biodiversity and the source of food and valuables medicines for humans.

Greenhouse effect and global warming.

Deforestation causes weather and climatic changes. When a large scale of trees aredestroyed by cutting and burning, it will reducerainfall, transpiration rate and the rate of usingcarbon dioxide during photosynthesis by plants.Clearing and burning of forests also release vast amounts of greenhouse gases such as carbon dioxide into the atmosphere. Deforestation is believed to contributeabout 20-30% of all carbon dioxide in the atmosphere for every year.Carbon dioxide can prevent heat from escaping from the atmosphere. Thus, the level of carbon dioxide increases and global temperature also increases. This leads to greenhouse effect and global warming. Increasing global temperature may change the ecosystem.

b) FARMING

Excessive use of land for farming and stock rearing lead to infertile land and may expose soil to erosion by wind.Use of inorganic fertilisers in farming also leads to eutrophication.

c) URBANISATION

Dumping of domestic waste as well as sewage discharge from houses causes pollution.The waste materials in landfills act as toxic substances which pollute nearby water sources.

INDUSTRIALISATION

Industrial plants discharge industrial and heated waste

water causing water pollution and thermal pollution.Toxic gases released by industries contribute to air

pollution.

BURNING •

Open burning of rubbish, farms and forests release more carbon dioxide into the atmosphere which aggravates the greenhouse effect.Burning of fossil fuels causes air pollution as well as increase the carbon dioxide content. As a result, it causes the greenhouse effect and global warming.

Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms.[1] Pollution can take the form of chemical substances or energy, such as noise, heat, or light. Pollutants, the elements of pollution, can be foreign substances or energies, or naturally occurring; when naturally occurring, they are considered contaminants when they exceed natural levels. Pollution is often classed as point source or nonpoint source pollution. The Blacksmith Institute issues an annual list of the world's worst polluted places. In the 2007 issues the ten top nominees are located in Azerbaijan, China, India, Peru, Russia, Ukraine, and Zambia.[2]

Air pollutionFrom Wikipedia, the free encyclopedia

Air pollution from World War II production

Smog over Santiago, Chile

Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere.

The atmosphere is a complex dynamic natural gaseous system that is essential to support life on planet Earth. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the Earth's ecosystems.

Indoor air pollution and urban air quality are listed as two of the world's worst pollution problems in the 2008 Blacksmith Institute World's Worst Polluted Places report.[1]

Pollutants

Main articles: Pollutant and Greenhouse gas

Before flue gas desulfurization was installed, the emissions from this power plant in New Mexico contained excessive amounts of sulfur dioxide.

Schematic drawing, causes and effects of air pollution: (1) greenhouse effect, (2) particulate contamination, (3) increased UV radiation, (4) acid rain, (5) increased ground level ozone concentration, (6) increased levels of nitrogen oxides.

A substance in the air that can cause harm to humans and the environment is known as an air pollutant. Pollutants can be in the form of solid particles, liquid droplets, or gases. In addition, they may be natural or man-made.[2]

Pollutants can be classified as primary or secondary. Usually, primary pollutants are directly emitted from a process, such as ash from a volcanic eruption, the carbon monoxide gas from a motor vehicle exhaust or sulfur dioxide released from factories. Secondary pollutants are not emitted directly. Rather, they form in the air when primary pollutants react or interact. An important example of a secondary pollutant is ground level ozone — one of the many secondary pollutants that make up photochemical smog. Some pollutants may be both primary and secondary: that is, they are both emitted directly and formed from other primary pollutants.

Major primary pollutants produced by human activity include:

Sulfur oxides (SOx) - especially sulphur dioxide, a chemical compound with the formula SO2. SO2 is produced by volcanoes and in various industrial processes. Since coal and petroleum often contain sulphur compounds, their combustion generates sulfur dioxide. Further oxidation of SO2, usually in the presence of a catalyst such as NO2, forms H2SO4, and thus acid rain.[2] This is one of the causes for concern over the environmental impact of the use of these fuels as power sources.

Nitrogen oxides (NOx) - especially nitrogen dioxide are emitted from high temperature combustion. Can be seen as the brown haze dome above or plume downwind of cities. Nitrogen dioxide is the chemical compound with the formula NO2. It is one of the several nitrogen oxides. This reddish-brown toxic gas has a characteristic sharp, biting odor. NO2

is one of the most prominent air pollutants. Carbon monoxide - is a colourless, odorless, non-irritating but very poisonous gas. It is a

product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.

Carbon dioxide (CO2) - a colourless, odorless, non-toxic greenhouse gas associated with ocean acidification, emitted from sources such as combustion, cement production, and respiration

Volatile organic compounds - VOCs are an important outdoor air pollutant. In this field they are often divided into the separate categories of methane (CH4) and non-methane (NMVOCs). Methane is an extremely efficient greenhouse gas which contributes to enhanced global warming. Other hydrocarbon VOCs are also significant greenhouse gases via their role in creating ozone and in prolonging the life of methane in the atmosphere, although the effect varies depending on local air quality. Within the NMVOCs, the aromatic compounds benzene, toluene and xylene are suspected carcinogens and may lead to leukemia through prolonged exposure. 1,3-butadiene is another dangerous compound which is often associated with industrial uses.

Particulate matter - Particulates, alternatively referred to as particulate matter (PM) or fine particles, are tiny particles of solid or liquid suspended in a gas. In contrast, aerosol refers to particles and the gas together. Sources of particulate matter can be man made or natural. Some particulates occur naturally, originating from volcanoes, dust storms, forest and grassland fires, living vegetation, and sea spray. Human activities, such as the

burning of fossil fuels in vehicles, power plants and various industrial processes also generate significant amounts of aerosols. Averaged over the globe, anthropogenic aerosols—those made by human activities—currently account for about 10 percent of the total amount of aerosols in our atmosphere. Increased levels of fine particles in the air are linked to health hazards such as heart disease,[3] altered lung function and lung cancer.

Persistent free radicals connected to airborne fine particles could cause cardiopulmonary disease.[4][5]

Toxic metals, such as lead, cadmium and copper. Chlorofluorocarbons (CFCs) - harmful to the ozone layer emitted from products currently

banned from use. Ammonia (NH3) - emitted from agricultural processes. Ammonia is a compound with the

formula NH3. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceuticals. Although in wide use, ammonia is both caustic and hazardous.

Odors  — such as from garbage, sewage, and industrial processes Radioactive pollutants - produced by nuclear explosions, war explosives, and natural

processes such as the radioactive decay of radon.

Secondary pollutants include:

Particulate matter formed from gaseous primary pollutants and compounds in photochemical smog. Smog is a kind of air pollution; the word "smog" is a portmanteau of smoke and fog. Classic smog results from large amounts of coal burning in an area caused by a mixture of smoke and sulfur dioxide. Modern smog does not usually come from coal but from vehicular and industrial emissions that are acted on in the atmosphere by ultraviolet light from the sun to form secondary pollutants that also combine with the primary emissions to form photochemical smog.

Ground level ozone (O3) formed from NOx and VOCs. Ozone (O3) is a key constituent of the troposphere. It is also an important constituent of certain regions of the stratosphere commonly known as the Ozone layer. Photochemical and chemical reactions involving it drive many of the chemical processes that occur in the atmosphere by day and by night. At abnormally high concentrations brought about by human activities (largely the combustion of fossil fuel), it is a pollutant, and a constituent of smog.

Peroxyacetyl nitrate (PAN) - similarly formed from NOx and VOCs.

Minor air pollutants include:

A large number of minor hazardous air pollutants. Some of these are regulated in USA under the Clean Air Act and in Europe under the Air Framework Directive.

A variety of persistent organic pollutants, which can attach to particulate matter.

Persistent organic pollutants (POPs) are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes. Because of this, they have been observed to persist in the environment, to be capable of long-range transport, bioaccumulate in human and animal tissue, biomagnify in food chains, and to have potential significant impacts on human health and the environment.

Water pollutionFrom Wikipedia, the free encyclopedia

Raw sewage and industrial waste flows across international borders—New River passes from Mexicali to Calexico, California.

Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans and groundwater). Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds.

Water pollution affects , plants, and organisms living in these bodies of water; and, in almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities.